This invention relates to fluid ball and socket couplings for connecting high pressure fluid hoses or for connecting a fluid supply high pressure hose to a spray nozzle.
U.S. Pat. No. 1,087,006 discloses a spray nozzle coupled to a hose with a ball and socket coupling comprising a metal ball connected in a metal socket that is spun about the ball to retain the socket on the ball. This arrangement is subject to leakage.
U.S. Pat. No. 2,557,106 discloses a similar device which suffers from a similar deficiency.
U.S. Pat. No. 2,971,701 discloses a ball and socket arrangement employing an O-ring in combination with a split ring. A coupling nut engages the ball. The split ring permits universal pivoting of the ball. In a further embodiment resilient fingers engage the ball to s bias the ball toward the split ring. In other embodiments a spring biases the ball.
In U.S. Pat. No. 3,022,014 a ball and socket arrangement is shown for a shower head. The ball is seated at one region against a packing and at another region is retained by a nut that has a shoulder that engages the ball.
U.S. Pat. No. 3,224,793 shows a ball and socket arrangement wherein an O-ring is used in combination with a split ring, the ring for retaining the ball in the socket.
In U.S. Pat. No. 3,334,818 to Moen, a swivel and socket arrangement is shown in which an adapter is threaded to a mounting member forming a socket. An O-ring seals against the swivel and against the adapter and mounting member. The adapter squeezes against the O-ring. An undescribed member also abuts the ball distal the adapter apparently for retaining the swivel in the socket in one axial direction. It appears that the O-ring holds the swivel axially in place so the swivel will not displace toward the adapter away from the retaining member in the opposite axial direction. This function, however, is not expressly described per se. The end of the swivel, which is ball shaped, adjacent to the adapter, is spaced from the adapter. It thus appears that the O-ring is both a seal and a retainer member.
In U.S. Pat. No 3,921,912 a spherical member and gudgeon arrangement for a lawn sprinkler is disclosed. An O-ring abuts the member in the socket of the gudgeon and the spherical member also abuts the socket of the gudgeon directly.
Metal to metal contact in certain of the above patent devices is undesirable as it causes galling. Galling creates metal chips which can harm the O-rings which are typically rubber and thus cause leakage. In others of the above patents, the O-ring serves as both a sealing member and a retaining member. Since O-rings are typically made of rubber or other elastomeric material, high pressure between the O-ring and the mating members creates relatively high friction. This friction interferes with the operation of such devices. In some cases, it is known that silicon grease may be used on the O-rings to reduce friction. However, eventually such grease dissipates, especially in the presence of hot fluids, and the high friction returns.
The present invention is directed to provide a solution to the above problems. A fluid coupling device according to the present invention comprises a male member with a spherical surface and a fluid receiving bore passing through the member in communication with opposing first and second ends of the member. A first means is arranged for fluid coupling the first end of the male member bore to a fluid receiving device. A housing has a chamber lying on an axis and has a first transverse dimension open at a third end and a fourth end with a reduced transverse dimension opening. The second male member end and at least a portion of said male member spherical surface are received in said chamber, said reduced dimension fourth end for retaining the male member in the chamber in a first direction along the axis.
A nipple member is included and comprises a nipple at one end and a coupling member at an opposing end, the nipple for receiving and coupling to a fluid source for supplying fluid to said male member fluid receiving bore, the coupling member and housing including mating means for axially attaching the nipple member to the housing for retaining the male member in the chamber in a second direction opposite the first direction.
First and second annular seat members are included and exhibit negligible friction on their surfaces, the seat members being located in the chamber in spaced axial relation along the axis and abutting the housing on an outer peripheral surface of the seat members, the seat members abutting the spherical surface in the spaced axial relation and arranged for receiving radial forces and axial forces from the spherical surface in respective opposing axial directions. Second means fluid seal the chamber between the housing and male member and the housing and nipple member.
The seat members preferably comprise polytetraflouride material at at least at the interface with the spherical member.
In one embodiment, the housing chamber is circular cylindrical, the seat members comprising circular rings.
In a further embodiment, the seat members each have inner inclined surfaces which contact the spherical surface of the male member.